Internal combustion engine



Nov. 12, 1940. F. N ALLINGER INTERNAL COMBUSTION ENGINE Filed Jan. 10, 1938 Jnrenlar 15 of higher anti-knock value.

Patented Nov. 1940 INTERNAL COMBUSTION ENGINE Fritz Nallinger, Stuttgart, Wurttemberg, Germany,

assignmto Daimler-Benz Aktiengesellschaft, Stuttgart-Unterturkheim, Germany Application January 10, 1938, Serial No. 184,175

Germany January 11, 1937 21 Claims.

This invention is concerned with internal combustlon engines in whichan increased torque can be obtained temporarily by the aid of a blower or charge booster generally known 'as a supercharger. In such engines, when a certain degree of compression or charging is exceeded, fuels of relatively low anti-knock value are liable to produce knock. This particularly applies to mixture-compressing engines, or Otto cycle engines,

working with a carburetter or withfuel injection into the cylinder.

The principal object of the present invention is to provide for the additional supply to the engine, when the charging is increased, of a fuel For this purpose,

a main fuel pump may operate continuously for the supply of fuel having a low anti-knock value,

an auxiliary fuel pump being provided for supply' of the fuel of higher anti-knock value.

2 The additional fuel may be a spirit, or a mixture containing ahigh percentage of spirit. Such fuel may be injected in appropriate quantities into theinduction passage, either in front of or beyond the blower and at one or more points, such injection being performed through suitably calibrated jets.

Several advantages are achieved by the invention in practice. First, a substantially higher degree of compression or charging without knock is possible. Second, additional injection of fuel,

particularly spirit, relieves the engine materially 45 craft engines, is important.

The annexed drawing illustrates one practical example and therein; l

Figure l is a sectional side elevation of an en- 50 gine adapted for operation in accordance with these improvements; and

Figure 2 is a transverse section through the upper partof one of the cylinders.

Figure 1 illustrates a block of four cylinders 55? and in Figure 2 a is one of the cylinders with inis ablower 5, Figure 1, mounted on one end of The j together. backs at starting, particularly in the case of airlet valve b and exhaust valve 0. Fuel is normally injected into the cylinder a through a nozzle d.

As seen in Figure l, the nozzles d are supplied with iuel by means of a pump e drawing from a tank I, the pump e being driven from the engine in the usual manner.'

Combustion air issupplied-to the engine at the valve 1) by an intake pipe h and on this pipe there the engine, with its impeller 57 running in a bearing 6. A shaft i geared with the crank shaft by pinions H), H runs in bearings 1 and 8 in the impelle'r and in a bearing 9 in the end wall of the crank case. One part of a clutch k is splined at [3 on the shaft i and is displaceable along the shaft by the linkage l2. The other half of the clutch is is on the impeller. Thus, by clutching or declutching the said clutch parts, the impeller is coupled or uncoupled with or from the shaft i. Instead of the dog clutch illustrated in Figure 1,

it is possible to employ a frictional or slipping clutch.

An additional injection nozzle, provided in accordance with the invention, is seen at m in Figure 2, in an elbow connection between the intake manifold h and the inlet b of the cylinder. As will be seen from Figure 1, the four similarly disposed nozzle m are connected by tubes with an additional fuel pump 0 which draws its supply from a small tank n. The pump 0 can be coupled with or uncoupled from the engine by means of a clutch p. In the example illustrated the spindle of the pump 0 is aligned with that of the pump e and the two spindles can be coupled or 35 uncoupled by the clutch p. The last-named may be operated by a clutch lever H connected by a link 16 with a pedal l5. In the said illustrated example, the link 5 is connected with the links 12 so that depression of the pedal l5 simul- 40 taneously closes the clutches p and k, whereby the pump 0 and impeller g willbe put into operation In some cases, the fuel pumps e and 0 may be comprised in a single constructional unit. I I

The operation is as follows: Normally, the clutches k and p are disengaged so that the blower 5 and additional fuel pump 0 are idle. In

this phase of operation, the engine runs on norgree of charging and compression is desired, the pedal 5 is depressed for closing the clutches la and p. Thereupon the'impeller g is driven from the engine for the production of the desired supercharging and simultaneously the additional pump 0 is driven for supplying the nozzles m with additional fuel drawn from the tank n. This additional fuel (spirit, for example) may have a high anti-knock value, so that there is an absence of knocking in spite of the higher duty which the engine is called upon to perform.

Adjustment of the output of the fuel pumps may be effected in any known or suitable manner. The quantity of fuel may also be regulated, for example, in dependence upon the clutching of the blower in such manner that the fuel is supplied to the nozzles d only up to a certain degree of regulation. When this degree is exceeded, the blower is set in operation and additional fuel is simultaneously injected. The operativeness of the additional pump may be controlled by means of a by-pass for example, instead of by means of a clutch. Thus, the additional pump may be rendered inoperative by opening its by-pass and may be brought into operation gradually or fully by an appropriate closing of the by-pass valve.

In some cases, injection of additional fuel of higher anti-knock value may be effected under hand control. Also, injection of this fuel may be affected at one or more points either in front of or beyond the blower, or even wholly or partly directly into the cylinders.

Accordingly, while I have described an illustrative embodiment of the invention, it is pointed out that various changes and modifications therein may be made without departing from the in- I vention as set forth in the claims which follow.

I claim:

1. In an internal combustion engine, in combination, a normal fuel supply means, controlled supercharging means, means for supplying a second fuel and a control adapted for rendering said last means operative in dependence upon operation of said supercharging means.

2. In an internal combustion engine, in combination, a normal fuel supply means, controlled supercharging means, a normally inoperative spirit fuel supply, and a control adapted for rendering said spirit fuel supply operative in dependence upon operation of said supercharging means. 3. In an internal combustion engine, in combinat ion, a constantly'operative normal fuel supply means, controlled supercharging means, means for supplying a second fuel, and a joint control adapted for rendering. said supercharging means and said last means either operative or inoperative in unison.

4. In an internal combustion engine having an intake manifold in combination, a normal fuel supply means, controlled supercharging means, means for supplying a second fuel connected with said intake manifold, and a control adapted for rendering said last means operative in dependence upon operation of said supercharging'means.

5. In an internal combustion engine having an intake manifold and inlet valves, in combination, a normal fuel supply means, controlled supercharging means, means for supplying a second fuel including fuel nozzles in the intake manifold between said supercharging means and said inlet valves, and a control adapted for rendering said second fuel supply means operative in dependence upon operation of said supercharging means. u

6. In an internal combustion engine, in combination, a normal fuel supply means. controlled supercharging means, means for supplying a second fuel connected with the supercharged side of said engine, and a control adapted for rendering said last means operative in dependence upon operation of said supercharging means.

7. In an internal combustion engine, incombination, a normal fuel supply means comprising jet nozzles opening into the combustion chambers,

controlled supercharging means, an additional fuel supply means, and a control adapted for rendering such additional means operative in dependence upon operation of said supercharging means.

8. In an internal combustion engine having an I intake pipe, in combination, a normal fuel supply means comprising injection nozzles delivering into the combustion chambers, a controlled blower on the intake pipe, an additional fuel supply means comprising injection nozzles in the intake pipe, and a control adapted for rendering such additional means operative in dependence upon operation of said blower.

9. In an internal combustion engine having an intake pipe,in combination, a normal fuel supply means comprising injection nozzles delivering into the combustion chambers, a controlled blower on the intake pipe, an additional fuel supply means comprising an injection nozzle delivering into the supercharged side of said engine, and a control adapted for rendering such additional means operative in dependence upon operation of said blower.

10. In an internal combustion engine, in combination, a normal fuel supply means, controlled supercharging means, means of relatively small capacity for supplying a second fuel, and a control adapted for rendering saidlast means operative in dependence upon operation of said supercharging means.

11. In an internal combustion engine, in combination, a fuel pump unit comprising a contill means, and a control adapted for rendering said intermittently running element operative in dependence upon operation of said supercharging means.

12. In an internal combustion engine, in combination, a constantly running normal fuel pump, a coaxial abnormal fuel pump, fuel delivery instruments connected with respective pumps, con-= trolled supercharging means, and a control adapted'for rendering said abnormal fuel pump operative in dependence upon operation of said supercharging means.

13. In an internal combustion engine, in combination, a normal fuel pump driven from the engine, an abnormal fuel pump clutchable with said normal fuel pump, connected with respective pumps, controlled supercharging means, and a control adapted for clutching in said abnormal fuel pump in dependence upon operation of said supercharging means.

14. Method of operating an internal combus tioin engine with supercharging, consisting in .normally supplying fuel of relatively low antiknock value for combustion, and additional supply of fuel having in effecting an a higher antiknock value during supercharging.

fuel delivery instruments 15. Method according to claim 14, consisting '15 further in continuously supplying fuel of low antiknock value for combustion and in effecting an additional supply of fuel having a higher antiknock value during supercharging.

16. Method according to claim 14, consisting further in delivering the additional fuel supply into the charging air before admission of the latter into the engine.

17. Method according to claim 14, consisting further in injecting normal fuel'directly into the cylinder and injecting additional fuelof higher anti-knock value into the charging air before admission of the latter into the engine.

18. The combination according 'to claim 1, wherein the means for supplying a second fuel includes a fuel having higher anti-knock characteristics than the fuel in said normal supply means.

19. The combination according to claim 5, wherein the means for supplying a second fuel includes a fuel having higher anti-knock characteristics than the fuel in said normal supply means 20. The combination according to claim 10, wherein the means for supplying a second fuel includes a fuel having higher anti-knock characteristics than the fuel, in said normal supply means.

21. In an internal combustion engine, in combination, a normal fuel supply means, a supercharger and driving means therefor, additional fuel supply means, and control means for con-'- comitantly rendering said additional fuel supply means and said supercharger driving means effective or ineffective.

FRITZ NALLINGER. 

